From a7102acb7ede81a02b3b35bb9f60e446b24acbce Mon Sep 17 00:00:00 2001
From: WO <wo@kotocoin.info>
Date: Fri, 31 Aug 2018 19:56:20 +0900
Subject: [PATCH] Add an assert for num_bits function

---
 src/snark/libsnark/algebra/fields/bigint.tcc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/snark/libsnark/algebra/fields/bigint.tcc b/src/snark/libsnark/algebra/fields/bigint.tcc
index 9088684fc..bbb89f476 100644
--- a/src/snark/libsnark/algebra/fields/bigint.tcc
+++ b/src/snark/libsnark/algebra/fields/bigint.tcc
@@ -124,6 +124,7 @@ size_t bigint<n>::num_bits() const
         }
         else
         {
+            static_assert(GMP_NUMB_MAX <= ULLONG_MAX, "coercing limb to unsigned long long might truncate");
             return ((i+1) * GMP_NUMB_BITS) - __builtin_clzll(x);
         }
     }